2pcore spectrum of atomic potassium: Comparison of binding energies and intensities with the Auger spectrum and with theory

Abstract

The $2P$ core region of atomic potassium has been studied with Al $K\ensuremath{\alpha}$ (1486.6-eV) radiation. Core binding energies of 300.56(6) eV for $2{p}_{\frac{3}{2}}$ and 303.31(6) eV for $2{p}_{\frac{1}{2}}$ electrons have been measured and compared with previous measurements and with theory. A satellite at 6.3 eV higher binding energy than the $2{p}_{\frac{3}{2}}$ peak with a relative intensity of (17.8\ifmmode\pm\else\textpm\fi{}1.0)% has been observed; an analogous satellite has also been observed for $2{p}_{\frac{1}{2}}$. Good agreement was found with calculations which assign the satellites to $4s\ensuremath{\rightarrow}5s$ excitation accompanying core ionization. Analogous satellites were identified in the ${L}_{2,3}{M}_{2,3}{M}_{2,3}$ and ${L}_{2,3}{M}_{2,3}{N}_{1}$ Auger spectra, and it was found that the background in the Auger spectra should be taken to be lower than previously assumed in order to get good agreement between the relative intensities obtained in the photoelectron and Auger studies. The photoelectron intensity ratio $\frac{{I}_{{2p}_{\frac{3}{2}}}}{{I}_{{2p}_{\frac{1}{2}}}}$ was found to be 1.75(7); this confirms the prediction of Dirac-Slater calculations that this ratio is less than the statistical value of 2.